1. Field of the Invention
The present invention relates to a wireless charger, and more specifically, to a receiver for a wireless charging system, which provides a new design structure for efficiently receiving power wirelessly transmitted from the wireless charger.
2. Background of the Related Art
Techniques of providing wireless transmission and reception units in an electronic device and accomplishing wirelessly charge are under development. Mobile communication terminals are developed in a variety of forms recently, and therefore, there are charging jacks as diverse as various forms of power chargers. Although a problem of compatibility between the chargers arises accordingly, since the charging jacks are standardized to a 24-pin charging jack, the problem of compatibility between the chargers has been solved for users.
However, since charging is still accomplished through a long cable wired between a charger and a device, users considerably suffer from troubles and inconvenience due to the limitation on distance. In addition, when a plurality of terminals is charged using one charger, there is a problem in that the users can be troubled due to manual attachment and detachment of the charger and the terminal jack or the terminal can be damaged due to abrasion or damages of a connection part.
However, since the specification and shape of a terminal are different among devices in a connection terminal type, users suffer from difficulties of repeatedly purchasing a new charging device, and this method generates a new problem of discarding previously used chargers when a new device is purchased.
In addition, a non-contact type magnetic induction method, i.e., a wireless charging method, has been devised to solve the above problems. The non-contact type charging method is a method of providing current of a charging parent, i.e., energy, to the battery of a portable electronic device through inductive coupling, by configuring a primary circuit operating at a high frequency in the charging parent and configuring a secondary circuit at the battery side, i.e., in a portable electronic device or the battery. The non-contact type charging method using the inductive coupling is already used in some application fields (e.g., an electric toothbrush, an electric shaver and the like).
However, when the non-contact type charging method is desired to be applied to a portable electronic device, such as a cellular phone, a portable MP3 player, a CD player, an MD player, a cassette tape player, a notebook computer, a PDA or the like, variation of charging efficiency generated according to the position of placing the portable electronic device or the battery should be improved, in addition to the required condition of reducing the volume and weight which will be added to the battery.
However, when the non-contact type charging method is applied to a cellular phone or a smart phone, needless to say that the variation should be improved, there is a problem in that since various types of wireless chargers are released in a predetermined method, the wireless chargers cannot charge a battery if the charging methods are different.
Furthermore, the non-contact type charging method provides only one coil, and a design specification between coils is not determined, and, in addition, an accurate structure of placing a coil in a terminal is not described.
That is, in prior art 1 (Korean Patent Registration No. 10-0928439), a lower core is provided to be placed between a first upper core (coil) and a second upper core, and a control unit determines which of the lower core, the first upper core and the second upper core receives a signal transmitted from a non-contact point power reception apparatus and controls transmission of a power signal through a corresponding core in correspondence to a result of the determination. However, a coil (antenna) having a composite function is not presented, and an optimal design condition or structure is not presented.
In addition, in prior art 2 (Korean Patent Registration No. 10-0971714), the inductive pattern core of the primary core unit is provided with a lower core layer having a plurality of cores formed on the top of a PCB base and an upper core layer having a plurality of cores formed on the top of a gap panel on the lower core layer, and although the lower core layer and the upper core layer are positioned to intersect with each other to be provided as multiple layers, a structure of a core (antenna) having a composite function is not presented, and an optimum design condition is not specifically presented.
In addition, although prior art 3 (Korean Patent Registration No. 10-1001262) provides a rechargeable cellular phone case including a support for detachably resting a portable terminal; and a charging module provided in the support to accomplish wireless charge when the portable terminal is rested on the support as the magnetic fields generated by the power supplied from outside are transferred to the portable terminal side by electromagnetic induction, it also does not present a structure of a core (antenna) having a composite function and does not specifically present an optimum design condition.
Accordingly, it is necessary to develop a wireless charging method having both a composite function and an optimum design condition.